A direct current (DC) motor is a machine that uses DC power to produce a torque force on a rotating member, or rotor, of the machine. In a typical DC motor, currents are applied to and removed from wire windings of the motor in accordance with a phase, or commutation, sequence; and this interaction of the currents with a magnetic field of the DC motor produces the torque force to rotate the rotor.
The ways in which the currents are commutated to the DC motor's winding vary among different DC motor topologies. One type of DC motor is a brushed DC motor, in which brushes mechanically commutate currents to wire windings of the rotor, and the stator of the brushed DC motor has permanent magnets or electromagnets that produce a stationary magnetic field. In a typical brushless DC motor (BLDC), permanent magnets are mounted to the rotor to produce a magnetic field; and semiconductor devices control the switching of currents with wire windings of the stator according the commutation sequence.